That being the case, the feat should probably not be attempted until another hand or two have been obtained, preferably with the person from whom they've been borrowed still attached, since in addition to the hands you'll also need someone to operate them.

As related question, anybody know how to make them function as actual function on a semi-permanent basis (like a function-lock?) It's always mildly annoying when I attempt to use them as game controls and wind up muting my sound.